CN103633649B - A kind of future-state alternating-current flow of power grid generates method - Google Patents

Abstract

The invention relates to a method for generating an AC power flow in the future state of a power grid. The method includes the following steps: 1) selecting a real-time operation section of the power grid as an initial section; 2) obtaining power generation plan data; 3) obtaining power grid maintenance plan data; 4) obtaining bus load forecast data; 5) obtaining tie line plan data; 6) Drive the power flow calculation of the primary grid; 7) Calculate the power deviation value of the tie line ;8) Correct load injection; 9) Drive primary grid power flow calculation; 10) Set the output adjustment status of each generator as the initial setting value, which is obtained from the rated parameters of the generator; 11) Save the grid after the adjustment is completed The cross-section successfully generated the future state trend. Based on the real power grid operation section, the present invention fully considers future prediction and planning data such as power generation plan, maintenance plan, tie line transaction plan, bus load forecast data, etc., automatically adjusts and generates future AC power flow; provides accurate future state forecast power flow As a result, complete basic power flow data are provided for planning safety checks.

Description

A method for generating AC power flow in the future state of power grid

technical field

The invention belongs to the technical field of electric power system scheduling automatic control, and in particular relates to a method for generating an AC power flow in the future state of a power grid.

Background technique

In order to ensure the safe and economical operation of the power grid, it is necessary to formulate the power generation plan, maintenance plan, and tie-line transaction plan of the power grid according to the predicted power grid load, and conduct a power grid security assessment for the formulated plan. Traditional planning systems usually use DC power flow to assess the safety of future grid power flow. Since the DC power flow does not consider the influence of reactive power and voltage, the calculation results have large errors, which affects the accuracy of power grid forecasting power flow. There are also large errors in the automatic fault scanning based on the DC power flow, which may cause serious hidden dangers to the safety of the power grid.

Contents of the invention

The purpose of the present invention is to solve the problem that it is difficult to accurately generate the AC power flow section in the future state, and propose a method for generating the AC power flow in the future state of the power grid. Based on the real grid operation section, the present invention fully considers future prediction and planning data such as power generation plan, maintenance plan, tie-line transaction plan, bus load prediction data, etc., and automatically adjusts and generates future AC power flow. The AC power flow strictly meets the output of power grid units formulated in the power generation plan, the change of the switch operation mode formulated in the maintenance plan, and the tie line power flow formulated in the tie line transaction plan, providing accurate future state forecast power flow results, and providing a complete set of plans for safety checks. basic power flow data.

In order to achieve the purpose of the above invention, the technical solution of the present invention is: a method for generating a power grid future state AC power flow, characterized in that the method includes the following steps:

1) Select a real-time operating section of the power grid as the initial section, adjust the grid operation mode and power generation load output to make the initial section meet the requirements of the typical operating section of the power grid; and save the section data as the basic section of the future AC power flow.

2) Obtain the grid power generation planning data, and obtain the active output of each generating set according to the set future state power flow time; in the basic section, set the active output of each generator as the active output of the generating plan; set the active output of each generating set The state of participating in the output adjustment of the unit is not participating in the adjustment, which means that when the grid has a power shortage during the power flow calculation process of this type of unit, the output of the unit remains unchanged.

3) Obtain the grid maintenance plan data, and obtain the state change of the switch switch in the maintenance plan according to the set future state power flow time; in the basic section, set the changed switch switch state.

4) Obtain the bus load forecast data, and obtain the load active and reactive power flows in the bus load forecast according to the set future state power flow time; in the foundation section, set the active power and reactive power injection flow of the load and the load in the bus load forecast The trend of active and reactive power is the same.

5) Obtain the data of the connection line plan, and obtain the total added value of the active power of the system connection line plan according to the set future state trend time ;Set the generator connected to the tie line as the external network unit; set the output adjustment status of the external network unit as automatic adjustment, which means that when the power shortage of the power grid occurs during the power flow calculation process of this type of unit, the output of the unit will automatically change to balance grid load.

6) Drive the power flow calculation of the primary power grid, and obtain the actual total added value of the tie line from the power flow calculation results . Since only the external grid unit participates in the automatic adjustment, the unbalanced power shortage between the grid power generation and the load can only be borne by the external grid unit. The value is determined by the actual external network unit output calculated by the power flow.

7) Calculate tie line power deviation value ;

8) Corrected load injection. Adjust the load injection power flow according to the deviation of the tie line, and distribute the deviation of the tie line to each load injection after considering the loss of the whole network, and provide the corrected load injection for the next power flow calculation;

9) Drive the power flow calculation of the primary grid to obtain the calculated actual total added value of the tie line , Tie line power deviation value ; When tie line power deviation value Less than the tie line deviation set value (Usually set to 0.005* ), the automatic correction of grid load ends, and proceed to step 10); when the tie line power deviation value Greater than the tie line deviation set value , 7)-9) cycle to achieve power grid load correction;

10) Set the output adjustment state of each generator as the initial set value, which is obtained from the rated parameters of the generator.

11) Save the grid section after the adjustment, and successfully generate the future state power flow.

The beneficial effects of the method of the present invention are:

On the one hand, the present invention is based on the real power grid operation section, and fully considers future forecast and planning data such as power generation plan, maintenance plan, tie line transaction plan, bus load forecast data, etc., and the power flow section generated meets the plan requirements. On the other hand, for the deviation between the planned unit output and the predicted load, the power grid load is automatically corrected to accurately match the unit output plan. The AC power flow forecast has high accuracy and good convergence, which is conducive to carrying out accurate safety checks on the basis of this power flow and improving the security of the power grid.

Advantages of the present invention are summarized as follows:

Fully consider future forecast and plan data such as power generation plan, maintenance plan, tie-line transaction plan, busbar load forecast data, etc., and predict power flow results accurately.

According to the predicted load given by the bus load forecast, the power grid load is automatically corrected to accurately match the unit output plan. The calculation speed is fast and the calculation error is small.

Description of drawings

Fig. 1 is a block diagram of an overall flowchart of a method for generating an AC power flow in a future state of a power grid according to an embodiment of the present invention.

detailed description

The method for generating the AC power flow in the future state of the power grid proposed by the present invention is described in detail in conjunction with the accompanying drawings and embodiments as follows:

The method for generating the AC power flow in the future state of the power grid proposed by the present invention, as shown in Figure 1, includes the following steps:

1) Select a real-time operating section of the power grid as the initial section, and adjust the grid operation mode and power generation load output to make the initial section meet the requirements of the typical operating section of the power grid. Save the cross-section data as the basic cross-section of the future state communication flow.

2) Obtain the grid power generation plan data, and obtain the active output of each generator set according to the set future state power flow time. In the basic section, set the active output of each generator to be the active output of the power generation plan; set the output adjustment status of each generator to not participate in adjustment, which means that when there is a power shortage in the power grid during the power flow calculation process of this type of unit, the unit will The output remains unchanged.

3) Obtain the grid maintenance plan data, and obtain the status changes of the switch and switch in the maintenance plan according to the set future state power flow time. In the basic section, set the changing switch switch state.

4) Obtain the bus load forecast data, and obtain the load active power and reactive power flow in the bus load forecast according to the set future state power flow time. In the foundation section, the active and reactive power flow of the set load is consistent with the load active and reactive power flow in the bus load forecasting.

5) Obtain the data of the connection line plan, and obtain the total added value of the active power of the system connection line plan according to the set future state trend time . Set the generator connected to the tie line as an external network unit; set the output adjustment status of the external network unit as automatic adjustment, which means that when this type of unit has a power shortage in the power grid during the power flow calculation process, the unit output will automatically change to balance the grid load.

6) Drive the power flow calculation of the primary power grid, and obtain the actual total added value of the tie line from the power flow calculation results . Since only the external grid unit participates in the automatic adjustment, the unbalanced power shortage between the grid power generation and the load can only be borne by the external grid unit. The value is determined by the actual external network unit output calculated by the power flow.

7) Calculate tie line power deviation value :

(1)

8) Corrected load injection. Adjust the load injection power flow according to the deviation of the tie line, and distribute the deviation of the tie line to each load injection after considering the loss of the whole network, and provide the corrected load injection for the next power flow calculation; the specific steps are as follows:

① Based on the last power flow calculation result, calculate the output value of the generating units in the whole network , the network-wide load injection value :

(2)

(3)

In formula (2), NG represents all units in the power grid; Indicates the active output value of the jth unit, which can be obtained from the power flow calculation results; Indicates the utility power consumption rate of the jth unit, which can be obtained from the rated parameters of the generator, and usually its value ranges from 0 to 0.2;

In formula (3), ND represents all loads in the grid; Indicates the active power injection value of the jth load, which can be obtained from the power flow calculation results;

②For the last power flow calculation result, calculate the network loss rate of the whole network :

(4)

③For the last power flow calculation result, calculate the load adjustment coefficient :

(5)

④ Correction of all load injection values :

(6)

9) Drive the power flow calculation of the primary grid to obtain the calculated actual total added value of the tie line , Tie line power deviation value ; When tie line power deviation value Less than the setting value of tie line deviation (Usually set to 0.005* ), the automatic correction of grid load ends, and proceed to step 10); when the tie line power deviation value Greater than the tie line deviation set value , 7)-9) cycle to achieve grid load correction;

10) Set the output adjustment state of each generator as the initial set value, which is obtained from the rated parameters of the generator.

11) Save the grid section after the adjustment, and successfully generate the future state power flow.

Claims (1)

1. a future-state alternating-current flow of power grid generates method, it is characterised in that the method comprises the following steps:

1) select an electrical network real time execution section as initial section, adjust power system operating mode and generation load is exerted oneself at the beginning of making Beginning section meets electrical network typical case and runs section requirement；And preserve this profile data basic section as future-state AC power flow；

2) obtain grid generation planning data, according to the future-state trend time set, obtain that each generating set is meritorious exerts oneself； In the section of basis, meritorious the exerting oneself setting each electromotor is exerted oneself for generation schedule is meritorious；Set each electromotor to participate in out Power adjusts state for not participating in adjustment, represent the type unit during Load flow calculation during electrical network emergent power vacancy, unit Exert oneself constant；

3) obtain maintenance scheduling for power systems data, according to the future-state trend time set, obtain repair schedule breaker in middle disconnecting link shape State changes；In the section of basis, set the switch tool state of change；

4) obtaining bus load prediction data, according to the future-state trend time set, obtaining load in bus load prediction has Merit, reactive power flow；In the section of basis, meritorious, the idle injection trend of assumed load predict with bus load in load meritorious, Reactive power flow is consistent；

5) obtaining interconnection planning data, according to the future-state trend time set, acquisition system interconnection plan is meritorious always to be added Value；Set the electromotor being connected with interconnection as outer net unit；Set outer net unit to participate in exerting oneself adjustment state as automatically Adjusting, expression the type unit is during Load flow calculation during electrical network emergent power vacancy, and unit output will change automatically with flat Weighing apparatus network load；

6) drive an electric network swim to calculate, from calculation of tidal current, obtain interconnection reality the most value added；

Owing to only outer net unit participates in automatically adjusting, the imbalance power vacancy of grid generation and load can only be by outer net unit Undertake,The actual outer net unit output that value is gone out by Load flow calculation determines；

7) dominant eigenvalues deviation value is calculated；

8) modified load injects；

Inject trend according to the deviation adjustment load of interconnection, after the deviation of interconnection is considered the whole network loss, be assigned to each load Inject, provide revised load to inject for Load flow calculation next time；

9) drive an electric network swim to calculate, obtain the interconnection reality calculated the most value added, dominant eigenvalues deviation value；When dominant eigenvalues deviation valueLess than interconnection error set point, interconnection error set pointIt is set to 0.005*, automatically revise network load and terminate, enter step 10)；When dominant eigenvalues deviation valueMore than interconnection error set pointTime, carry out step 7) 9) circulation realize network load correction；

10) set each electromotor and participate in adjustment state of exerting oneself as initial set value, obtain from the nominal parameter of electromotor；

11) preserve the electrical network section after having adjusted, be successfully generated future-state trend.